Could have been a head gasket leak at some point ruining the lubricity factor

Could be the oiling grooves on thrust bearing were not milled enough

Could be a ballooning torque converter

Could be high pressure in the transmission lines (so I've read, and my pressure was high)

As it's been difficult to find the culprit, I am doing what I can and crossing my fingers. Replacing engine and torque converter. Also had transmission line pressured adjusted back down to where it is supposed to be.

I wonder if these bearings or crank were original? There was a number paint markered into the back of the crank where it meets the flex plate. And two marks on the thrust bearing cap.

Hope this next engine survives and that this will be helpful for someone down the line.

I would not trust the 130 K miles reading, the gauge assy could have been swapped out. Sounds way too low for a 91. Sounds like some small piece of metal thing failed and did the damage but I am not the expert of the guts of the crank area. Or PO let it run out of oil and it did the early damage before you bought it then it failed later.

Honestly. after my experience with a shop my friend said did good work. I can say maybe the engine was rebuilt. or like said above. ran wrong
I took my engine to b&b automotive in mesa arizona.

first the guy told me he could not fix my head without destroying it.
. I should have gone and picked them up right there and then.
not only did they grind the crank journals to two different specs.
but they ground the trust bearing as the wrong one.....
oh and this took them 4 weeks.

end all if you did not build it. you do not know what happened.
could be morons like the shop I went to.

I have seen paint markings on factory engines.ita not uncommon. But there's also junkyards that do the same. Without seeing it's hard to see.your pics aren't working for me, it says I need permission?.

There's also the possibility that the bearing just failed because it failed. If there's not a lot of evidence of failure, like multiple failed bearings from low oil, it's totally possible the thrust bearing was defective from the get go.

I agree, but used good working pulls are soooo dirt cheap, I would not bother trying to rebuilding that one. I would just swap it out for a known good used engine.

Quote:

Originally Posted by trippled

I have seen paint markings on factory engines.ita not uncommon. But there's also junkyards that do the same. Without seeing it's hard to see.your pics aren't working for me, it says I need permission?.

There's also the possibility that the bearing just failed because it failed. If there's not a lot of evidence of failure, like multiple failed bearings from low oil, it's totally possible the thrust bearing was defective from the get go.

It's time for a new engine and to put that one on the back burner for a rebuild in the garage somewhere. You're going to need a good machinist to inspect both the crank and the block. And the cam, if you plan on keeping it. It ain't moving that far without contaminating the oil with metallic debris.

... my god, are those Clevite bearings really from 77 AD? I didn't know they were in business that long. I didn't even know bearings existed back then

Since the bearings are marked 2-97, it is abundantly apparent this engine has been rebuilt at some point in the past.. and apparently, poorly.

I'll bet they didn't check the crankshaft end play, set it up too tight. It wore in, and the wear metals set up an accelerated wear throughout the system, but especially there.

Block and journals most definitely bear a complete, and close, inspection. Someone made a good point about good used pulls being cheap, but even then it's a bit of a crapshoot. That said, I will be doing the same in my 90, shortly.

wow. thats the worst crank I have ever seen in an xj.
And I ran mine with about 1/2 oil for 2 weeks when I first got it. I was 17 and uneducated.
you want to get it looked at by a machine shop before you throw any more money at it.